Cyngor Bro Morgannwg
Vale of Glamorgan Council

Remove allocation.

The attached, in my view raises important questions regarding the potential flood risk to existing properties downstream of HG1 KS4. the Authority are required to provide evidence that the requirements of TAN15 are met. Now, not at some future date.

HG1 KS3 LAND AT READERS WAY, RHOOSE
Flood Risk to existing properties
The RLDP provides no evidence that surface water flow, SuDS capacity, exceedance routes or downstream drainage have been assessed. Without this, the Council cannot show that development would not increase flood risk to properties downhill of the site. The allocation is therefore unsound and high risk and should be removed.

The allocation is premature and unjustified
Until the Council can demonstrate—through strategic evidence rather than future planning applications—that:
• Flood risk can be fully mitigated,
• Downstream properties will not be exposed to increased hazard, and
• Drainage infrastructure can cope with additional flows,
Without the above, the allocation should not proceed.
For the reasons above, the Land at Readers Way (SP4 KS3) should be immediately removed from the RLDP on the grounds that the site is unsound, insufficiently evidenced, and poses an unacceptable and unmitigated flood risk to existing communities located downhill, including my property and dozens of others along the south western boundary.

HG1 KS3 LAND AT READERS WAY, RHOOSE
Flood Risk to existing properties - insurance implications.
As a result of the above, there are insurance implications for existing properties on the south western boundary of HG1 KS3
This proposal shows catchment basins right along our boundary. If they have any risk of overflowing, the main insurance implications fall into three areas: our own home insurance, the developer’s liability, and future insurability of our property. The specifics depend on how the basins are designed, maintained, and whether they increase the flood risk to existing properties to the south west. All remain unanswered by the LDP.
This will affect our own home insurance – and that of all existing properties along the south western boundary of the site.
Overflowing basins can change how our insurers view our property’s risk profile. As follows: -
1. Increased flood risk classification
If runoff from the basins could reach our garden or home, insurers will treat our property as being at higher flood risk. This will lead to: -
• Higher premiums
• Higher excesses for flood related claims
• In some cases, fewer insurers willing to offer cover

Increased flood risk fails the requirements of TAN15
The RLDP provides no evidence that surface water flow, SuDS capacity, exceedance routes or downstream drainage have been assessed. Without this, the Council cannot show that development would not increase flood risk to properties downhill of the site. The allocation is therefore unsound and high risk and should be removed.
I am strongly objecting to the proposed allocation of Land at Readers Way, Rhoose (SP4 KS3) within the Replacement Local Development Plan 2021–2036. My property lies downhill to the south‑west of the proposed site. This topographical relationship creates a direct and unavoidable surface water flood risk to existing homes that has not been addressed in the RLDP evidence base.
1. Natural topography creates inherent flood risk
The Readers Way site sits at a higher elevation and drains naturally toward the south‑west, directly toward existing residential areas including CF62 3FT. This means that any increase in impermeable surfaces will accelerate and concentrate surface water flows downhill. This is a structural constraint, not a design detail, and cannot be fully mitigated at plan stage.
2. Lack of evidence that flood risk can be mitigated
The RLDP does not provide: -
• A strategic flood consequences assessment for this allocation.
• Any modelling of overland flow routes toward the south‑west.
• Evidence that SuDS features can be accommodated at sufficient scale to prevent increased run‑off.
• Assessment of exceedance events (extreme storms) and where water will flow when drainage systems are overwhelmed.
• Confirmation that downstream drainage infrastructure has capacity for additional discharge.
Without this evidence, the allocation fails the requirement in TAN 15 that development must not increase flood risk to third parties.
3. Existing surface water vulnerability downstream
Natural Resources Wales surface water maps already show areas of surface water accumulation within the surrounding streets. Allocating a major housing site upstream of an area with known surface water issues is contrary to national policy and introduces unacceptable cumulative risk.
4. Exceedance routes cannot be guaranteed at LDP stage
Safe exceedance routes depend on detailed design, ground modelling, and drainage engineering. None of this is available at LDP stage. Without it, the Council cannot demonstrate that water will not be directed toward existing homes during heavy rainfall. This makes the allocation unsound under the tests of deliverability and justification.
5. The allocation is premature and unjustified
Until the Council can demonstrate—through strategic evidence rather than future planning applications—that:
• Flood risk can be fully mitigated,
• Downstream properties will not be exposed to increased hazard, and
• Drainage infrastructure can cope with additional flows,
Without the above, the allocation should not proceed.
For the reasons above, the Land at Readers Way (SP4 KS3) should be immediately removed from the RLDP on the grounds that the site is unsound, insufficiently evidenced, and poses an unacceptable and unmitigated flood risk to existing communities located downhill, including my property and dozens of others along the south western boundary.

Insurance implications for existing properties on the south western boundary of HG1 KS3
This proposal shows catchment basins right along our boundary. If they have any risk of overflowing, the main insurance implications fall into three areas: our own home insurance, the developer’s liability, and future insurability of our property. The specifics depend on how the basins are designed, maintained, and whether they increase the flood risk to existing properties to the south west. The patterns below are relevant to HG1 KS3 and remain unanswered by the LDP.
This will affect our own home insurance – and that of all existing properties along the south western boundary of the site.
Overflowing basins can change how our insurers view our property’s risk profile. As follows: -
1. Increased flood‑risk classification
If runoff from the basins could reach our garden or home, insurers will treat our property as being at higher flood risk. This will lead to: -
• Higher premiums
• Higher excesses for flood‑related claims
• In some cases, fewer insurers willing to offer cover
This aligns with UK insurance guidance emphasising that new developments must remain insurable and should not worsen flood risk for neighbours.
2. Planning and drainage obligations
This plan does not demonstrate that the new drainage systems (including basins) does not increase flood risk to neighbouring land. This is part of national planning and flood‑risk policy. See also my previous comments pn the high risk nature of this proposal..
3. Maintenance responsibilities
Catchment basins require ongoing maintenance. If the Authority fails to maintain them and overflow occurs, liability falls on them. Maintenance will be required weekly due to regular wind-blown debris on recycling days
Long‑term implications
1. Impact on property value
2. Mortgage and insurance availability - Because insurance is a prerequisite for most mortgages, anything that jeopardises insurability can affect future buyers. UK guidance stresses that developments should not create uninsurable situations.

Photographs of historic run-ff flooding and highway flooding at Fontygary Inn traffic lights. Previously forwarded, with others to the Flood and Coastal Erosion Risk Management team at their request.
Flooding at Fontygary Inn traffic lights 19.11.24, The access into Fontygary Leisure Park was also flooded, preventing access. I have no photographs of that.
Run off showing mud content which leaves a muddy slurry all over Celtic Way creating a slip hazard.
Run-off is usually over prolonged periods. This time overnight and through the following day. Essentially every time it rains. This is a regular occurrence – 12 times since Christmas and over the 35 years we’ve lived here.
The site of the proposed development HG1 KS3 is often completely waterlogged with large areas of standing water. The extreme rum-off to the south west is a result every time it rains. This is not an extreme event.